Alcoholism and Cognition: The brain bounces back
It will not come as a surprise that alcohol has a detrimental impact on our cognitive processes. These involve such core functions as perceiving the world, forming memories, using and understanding language, and solving problems and decisions.[1] Over time, with repeated and excessive alcohol exposure, these deficits in normal functioning become engrained and persistent – leading to what we might crudely call brain damage. Problematic alcohol usage is understood as continuing to drink despite knowing the negative consequences. However recent studies show the neuroplasticity of the brain, with just two weeks of abstinence already showing notable strides in the recovery of one’s cognition. We will consider these deficits and neuroplasticity in more detail, along with those cognitive impairments that remain chronic for problematic alcohol users. This review is split into two parts: this is Part II: The brain bounces back.
Despite the numerous studies into the damaging effect of alcohol upon cognition, research is now showing the regenerative properties of the brain. Using MRI, one study showed that in as little as two weeks of abstinence, the brains of alcoholics start to restore some of their damaged grey matter.[2] These researchers were able to demonstrate the positive effect of this healing brain tissue across twelve areas of cognitive function – including their IQ, verbal fluency, speed of processing, working memory, attention, problem solving, impulsivity, verbal learning, verbal memory, visual learning, visual memory and visuospatial abilities. This same heartening effect on cognitive performance was observed in recovering alcoholics over six months later. This suggests just how plastic the brain is; that just a couple of weeks of sobriety can initiate the repair process. Another study suggested neurogenesis as being the mechanism responsible – in other words, the birth of new brain cells.[3] However the study, conducted in 2004, does also suggest that there is only a partial reversal of the cognitive damage engendered by excessive alcohol consumption. Therefore, the reality is not quite a vision of a restoration to full brain health.
Furthering this suggestion that some cognitive damage cannot be reversed, one study showed how deficits are still found in long-term abstaining alcoholics (those who have been sober for a month or more). In real concrete terms, this meant they processed information more slowly, had more difficulty learning new material, as well as showing deficits in abstraction and problem solving. The most commonly reported cognitive deficit experienced by recovering alcoholics was reduced visuospatial activity – in other words, difficulty dealing with objects in a 2D or 3D space. So whilst neurogenesis might mean that some cognitive abilities are restored when people go sober for two weeks or more, some functions are irrevocably damaged.
The same study also explained that other factors – like age, gender, other medical issues, diet, or even the motivation of the person to engage in cognitive measurement tasks – would affect their cognitive performance in sobriety. For example, 50-85% of alcoholics who took part in the study showed the above symptoms of cognitive decline, meaning a possible 15-50% of alcoholics may not show any signs of cognitive impairment once sober. Since this study, research has focused more on specific groups of abstinent alcoholics classed on these various factors, to try and pin down what makes some people particularly vulnerable to chronic cognitive impairment. To take one recent example, one review showed how abstaining women recover more in the cognitive areas of abstraction, but not so much in the area of perceptuomotor ability (such as hand-eye coordination). They also showed an overall slightly lower percentage of cognitive recovery, with 41% of women showing cognitive improvements with abstinence, compared to 46% of men.[4] Thus, the variability in how alcoholics “spring back” cognitively is evidently due to a multitude of factors making one more or less vulnerable to chronic brain damage.
Ultimately, though alcohol causes numerous cognitive deficits through the mechanisms of neurotransmitter inhibition and neurotoxicity, as well as interacting with vitamin B deficiencies, many of these functions can be restored in sobriety over weeks and months. The neuroplasticity to recover from this kind of damage highly varies based on characteristics of the individual, which intersects with gender, age, diet and motivation, amongst other factors. However, despite this optimistic research, there are a number of cognitive areas which are damaged beyond repair in those with severe alcoholism. Much of this damage is concentrated in the frontal lobe, meaning there are chronic impacts on daily functioning and so-called “higher thinking.”
Check out Part I: The damage of drinking.
References
[1] Evert DL, Oscar-Berman M. (1995) Alcohol-Related Cognitive Impairments: An Overview of How Alcoholism May Affect the Workings of the Brain. Alcohol Health Res World. 19(2):89-96.
[2] Stavro, K., Pelletier, J. & Potvin, S. (2012). Widespread and sustained cognitive deficits in alcoholism: A meta-analysis. Addiction Biology. 18, 203–213.
[3] Nixon K, Crews FT. (2004) Temporally specific burst in cell proliferation increases hippocampal neurogenesis in protracted abstinence from alcohol. Journal of Neuroscience. 24:9714–9722.
[4] Fama R, Le Berre AP, Sullivan EV. (2020) Alcohol's Unique Effects on Cognition in Women: A 2020 (Re)view to Envision Future Research and Treatment. Alcohol Res. 40(2):03.